The present invention relates to a particular novel class of substituted polysiloxane hydrides and correspondingly substituted polysiloxane-polyoxyalkylene copolymers, the utility of the hydrides such as in forming said copolymers, and to the use of the copolymers in the formation of cellular urethane products, particularly flexible urethane foam.
It is well known that the urethane linkages of cellular urethanes are formed by the exothermic reaction of a polyfunctional isocyanate and a polyfunctional active hydrogen-containing compound in the presence of a catalyst, and that the cellular structure is provided by gas evolution and expansion during the urethane-forming reaction. Illustrative of suitable active hydrogen-containing compounds are polyether polyols and polyester polyols. In accordance with the "one-shot" process which is the most widely used industrial technique, direct reaction is effected between all of the raw materials which include the polyisocyanate, the active hydrogen-containing compound, the catalyst system, blowing agent and surfactant. A major function of the surfactant is to stabilize the urethane foam, that is, prevent collapse of the foam until the foamed product has developed sufficient gel strength to become self-supporting.
In recent years considerable effort has been expended and continues in the development of silicon-containing compositions that are not only effective urethane foam, but which also help improve processing latitude and the quality of the foam product. For example, stabilizers which have good potency help expand the processing latitude of the foam manufacture, while stabilizers which in addition to having the ability to stabilize non-flame-retarded cellular urethane foam, but also offer utility as stabilizers of such foam having a flame-retardant incorporated therein are very desirable. In addition stabilizers which will improve the properties, e.g. breathability of open-celled flexible polyurethane foam are also very desirable.
Thus, it is an object of this invention to provide a new class of polysiloxane-polyoxyalkylene copolymers which in addition to being effective stabilizers for polyurethane foam also have excellent potency and help serve to improve the quality of the foam product.
Various other objects and advantages of this invention will become apparent to those skilled in the art from the accompanying description and disclosure.